所属领域:
钍基熔盐堆核能系统
资源类型:
天文学、地球科学
/ 地质学
文献作者:
EISEN, MS; MARKS, TJ
文献发表年份:
1994
文献期刊:
JOURNAL OF MOLECULAR CATALYSIS
文献摘要:The adsorption of organoactinide complexes on dehydroxylated alumina (DA) yields coordinatively unsaturated, highly active catalysts for several demanding chemical transformations. Thus, in the case of Th(eta3-allyl)4 supported on dehydroxylated gamma-alumina (DA), facile arene hydrogenation and alkane activation processes can be effected in slurry reactions at 90-degrees-C and P(H2) = 30-180 psi. Benzene reduction occurs at a turnover frequency of almost-equal-to 25000 h-1 per active site and cyclohexane C-H exchange with D2 at almost-equal-to 1300 h-1 per active site. Active site characterization using D2O poisoning, hydrogenolysis, and CH3Cl dosing indicates less-than-or-equal-to 8 +/- 1 % of the Th surface sites are catalytically significant. EPR and XPS spectroscopy provide no evidence for Th oxidation states less than +4. The mechanisms for the above processes are discussed in terms of electrophilic ''four-center'' activation processes in which the active sites appear to bear sterically significant, nonhydridic ancillary ligation.
文献类型: Article
文献语种: English
关键词: ALKANE ACTIVATION; ALLYL COMPLEXES; ARENES; HETEROGENEOUS CATALYSIS; HYDROGENATION; THORIUM
文献作者地址: TECHNION ISRAEL INST TECHNOL,DEPT CHEM,IL-32000 HAIFA,ISRAEL; NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208